Power transmission line monitoring system, power transmission line monitoring method, and power transmission line monitoring program

Abstract

To provide a technique which can accurately measure a separation between an overhead transmission line and a ground surface shape while reflecting deviation generated on the ground surface shape and reduce time, cost or the like needed for measurement in this case.SOLUTION: A power line monitoring system comprises: an initial value data acquisition part 12 which acquires three-dimensional data measured about a ground surface shape 5 of an arrangement region of an overhead transmission line 2 using a flight vehicle as initial value data; a displacement magnitude data acquisition part 12 which acquires and analyzes observation data periodically transmitted from a satellite 31 about the ground surface shape 5 and extracts temporal displacement magnitude of the ground surface shape 5 to make it displacement magnitude data; an installation information holding part 13 which holds installation information of the overhead transmission line 2; and a separation detection processing part 15 which calculates a separation between the overhead transmission line 2 and the ground surface shape 5 using the initial value data, the displacement magnitude data and the installation information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power transmission line monitoring system, a power transmission line monitoring method, and a power transmission line monitoring program. [Background technology]

[0002] Trees, buildings, and the like may exist on the ground surface in the area where the overhead power transmission line is located. The distance (separation) that the overhead power transmission line must be separated from the ground surface shape including such objects is specified. The separation between the overhead power transmission line and the ground surface shape is sometimes measured, for example, using a laser measuring device mounted on a helicopter (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-313715 Summary of the Invention [Problem to be solved by the invention]

[0004] The ground surface shape may change over time, but the object of the present disclosure is to provide a technology that can accurately measure the distance between an overhead power line and the ground surface shape while reflecting the changes that occur in the ground surface shape, and even in such a case, can reduce the time and cost required for measurement. [Means for solving the problem]

[0005] According to one aspect of the present disclosure, an initial value data acquisition unit that acquires three-dimensional data of a ground surface shape in an area where the overhead power transmission line is arranged, the data being measured using an aircraft, as initial value data; a displacement amount data acquisition unit that acquires and analyzes observation data regarding the earth's surface shape periodically transmitted from a satellite, extracts a displacement amount of the earth's surface shape over time, and sets the displacement amount data; An installation information storage unit that stores installation information of the overhead power transmission line; a distance detection processing unit that calculates a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power transmission line monitoring system is provided, comprising:

[0006] According to another aspect of the present disclosure, An initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage procedure for storing installation information of the overhead power transmission line; a distance detection process step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A method for monitoring a power transmission line is provided, comprising:

[0007] According to yet another aspect of the present disclosure, On the computer, an initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage step of storing installation information of the overhead power transmission line; a distance detection processing step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power line monitoring program is provided that causes the power line monitoring program to execute the following: Effect of the Invention

[0008] According to the present disclosure, the distance between an overhead power line and the ground surface shape can be accurately measured while reflecting the displacement occurring in the ground surface shape, and even in this case, the time and cost required for measurement can be reduced. [Brief description of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram illustrating a schematic configuration example of a power transmission line monitoring system according to an embodiment of the present invention; [Diagram 2] 1 is a flowchart showing an example of a procedure of a power transmission line monitoring method according to an embodiment of the present invention. [Diagram 3] FIG. 2 is an explanatory diagram showing a specific example of an SAR image processed by the power transmission line monitoring method according to the embodiment of the present invention. [Figure 4] 1 is an explanatory diagram (part 1) showing a specific example of three-dimensional coordinate space data processed by a power transmission line monitoring method according to an embodiment of the present invention. [Diagram 5] 1 is an explanatory diagram (part 2) showing a specific example of three-dimensional coordinate space data processed by the power transmission line monitoring method according to one embodiment of the present invention. FIG. [Figure 6] 1 is an explanatory diagram showing a specific example of a resolution conversion process in a power transmission line monitoring method according to an embodiment of the present invention; [Figure 7] FIG. 11 is an explanatory diagram (part 3) showing a specific example of three-dimensional coordinate space data processed by the power transmission line monitoring method according to one embodiment of the present invention. [Figure 8] FIG. 4 is an explanatory diagram (part 4) showing a specific example of three-dimensional coordinate space data processed by the power transmission line monitoring method according to one embodiment of the present invention. [Figure 9] FIG. 2 is an explanatory diagram showing a specific example of a power line sag calculation in the power transmission line monitoring method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Insights gained by the inventor> First, the findings of the inventors of the present application will be described.

[0011] The ground surface shape around overhead power lines needs to be kept clear of the overhead power lines, but it may change over time due to the growth of trees that make up the ground surface shape, the effects of disasters, etc. Therefore, it is necessary to periodically measure the clearance between the overhead power lines and the ground surface shape to determine whether there is an abnormality.

[0012] The measurement of the distance between the overhead power transmission line and the ground surface shape can be performed with high accuracy by measuring the ground surface shape using a laser measuring device mounted on a helicopter, as disclosed in Patent Document 1, for example. However, when measuring the distance periodically, there is a risk that the measurement costs will be excessive due to helicopter usage fees and maintenance costs for the laser measuring device. Also, in bad weather, it may not be possible to fly the helicopter, and measurements may not be possible when needed.

[0013] Meanwhile, in recent years, a technology has been known that uses radio waves from artificial satellites to observe the earth's surface, such as Interferometric SAR (Synthetic Aperture Radar), and images the strength of the waves reflected from the earth's surface, thereby making it possible to determine the state of the earth's surface. However, the SAR images obtained by Interferometric SAR can only measure the amount of displacement of the state of the earth's surface. In other words, although SAR images are suitable for extracting the amount of displacement of the state of the earth's surface by using the difference between multiple images, it is difficult to accurately obtain, for example, the absolute value of the height of a tree using SAR images alone, so they are not used for grasping the shape of the earth's surface around overhead power lines.

[0014] As described above, the existing technologies cannot be said to be suitable for periodic measurement of the distance between the overhead power transmission line and the ground surface. As a result of intensive research into this point, the inventors of the present application came up with the idea that by focusing on the advantages of a number of technologies that were originally used for different purposes and making them usable, it may be possible to perform periodic measurement of the distance with high accuracy at low cost without depending on the weather, etc.

[0015] In addition, the distance between an overhead transmission line and the ground surface shape is affected by the sag of the overhead transmission line. However, the occurrence mode of the sag of the overhead transmission line (degree of sagging) may vary depending on the magnitude of the current, weather conditions, etc., and it is difficult to grasp it accurately using a laser measuring device, SAR images, etc. As a result of extensive research into this point, the present inventors have come up with the idea that accurately grasping the sag of the overhead transmission line is very useful for suitably measuring the distance between the overhead transmission line and the ground surface shape.

[0016] The present disclosure is based on the above-mentioned novel idea discovered by the inventors of the present application.

[0017] <One embodiment of the present disclosure> (1) Configuration of power transmission line monitoring system Next, a configuration example of a power transmission line monitoring system will be described. FIG. 1 is an explanatory diagram that illustrates a schematic configuration example of a power transmission line monitoring system according to this embodiment.

[0018] (Overall composition) The power transmission line monitoring system of this embodiment is configured to periodically measure the distance between an overhead power transmission line 2 supported by a steel tower 1 and a ground surface shape 5 including trees 3, structures 4, etc. in the surrounding area in order to monitor whether there is any abnormality in the distance between them.

[0019] For that purpose, the power transmission line monitoring system includes at least a server device 10 having a function as a computer, and a temperature sensor unit 20 attached to the overhead power transmission line 2. The server device 10 and the temperature sensor unit 20 are communicatively connected via a communication line network 23. For that reason, the server device 10 may be installed in a place remote from the overhead power transmission line 2. The temperature sensor unit 20 will be described in detail later.

[0020] (Server device) The server device 10 is communicably connected to a ground station 32 that receives observation data from an artificial satellite 31. The observation data from the artificial satellite 31 is exemplified by an SAR image of the ground surface shape 5 around the overhead power transmission line 2. In other words, the server device 10 is capable of receiving a service of providing an SAR image of the ground surface shape 5 around the overhead power transmission line 2.

[0021] The server device 10 also has hardware resources such as a storage device 11 for storing various information and a CPU (Central Processing Unit) (not shown). The CPU executes a predetermined program preinstalled in the server device 10, so that the server device 10 functions as an initial value data acquisition unit 12, a displacement amount data acquisition unit 12, an installation information storage unit 13, a wire sag calculation unit 14, a separation detection processing unit 15, and a matching processing unit 16.

[0022] The initial value data acquisition unit 12 has a function of acquiring three-dimensional data of the ground surface shape 5 around the overhead power transmission line 2 (i.e., the ground surface shape 5 of the area in which the overhead power transmission line 2 is located) measured using a laser measuring device mounted on an aircraft such as a helicopter or drone, as initial value data of the ground surface shape 5. The measurement of the three-dimensional data using the aircraft may be performed using known technology. Moreover, the acquisition of the actual measurement results may be performed via the communication network 23 or using a computer-readable recording medium, and the method is not particularly limited. The initial value data is stored and held in the storage device 11 as necessary and organized into a database.

[0023] The displacement amount data acquisition unit 12 has a function of acquiring and analyzing the SAR images, which are observation data from an artificial satellite 31, periodically transmitted via a ground station 32, and extracting the amount of displacement over time of the ground surface shape 5 around the overhead power transmission line 2 to obtain the amount of displacement data. The ground station 32 transmits SAR images at a frequency of, for example, about once every few days. The transmitted SAR images and the displacement amount data extracted based on them are stored and held in the storage device 11 as necessary and organized into a database.

[0024] The installation information storage unit 13 has a function of storing installation information of the overhead transmission line 2 in a database by utilizing a predetermined area of ​​the storage device 11. The installation information of the overhead transmission line 2 is information for identifying the location where the overhead transmission line 2 is installed. Specifically, information on the tower 1 supporting the overhead transmission line 2, such as the latitude, longitude, height above ground, span length, and position and length of cross arm, is exemplified. However, as long as the installation location of the overhead transmission line 2 can be identified, the information is not limited to these and may include other information. The installation information may be input to the server device 10 by a known method, such as using an information input unit or a communication unit (not shown).

[0025] The electric wire sag calculation unit 14 has a function of calculating the sag of the overhead transmission conductor 2 by using the temperature measurement data obtained by the temperature sensor unit 20. The method of calculating the sag of the overhead transmission conductor 2 is not particularly limited, and a specific example thereof will be described later.

[0026] The separation detection processing unit 15 has a function of calculating the separation between the overhead transmission line 2 and the surrounding ground surface shape 5, using the initial value data acquired by the initial value data acquisition unit 12, the displacement amount data extracted by the displacement amount data acquisition unit 12, and the installation information held by the installation information holding unit 13, and judging the presence or absence of an abnormality in the calculated separation. In calculating the separation, the separation detection processing unit 15 may take into account the sag of the overhead transmission line 2 calculated by the electric wire sag calculation unit 14.

[0027] The matching processing unit 16 is a function that performs a process of matching the initial value data acquired by the initial value data acquisition unit 12 with the SAR image that is the basis of the displacement amount data extracted by the displacement amount data acquisition unit 12. The process performed by the matching processing unit 16 includes various processes for matching the initial value data with the SAR image, and a specific example of such a process is a resolution conversion process that matches the resolution of the initial value data with the resolution of the SAR image. The details of the matching process such as the resolution conversion process will be described later.

[0028] (program) As described above, the functions of the units 12 to 16 are realized by the CPU executing a predetermined program. The predetermined program that causes a computer to execute these functions corresponds to an example of a power transmission line monitoring program according to the present disclosure.

[0029] In this case, if the power line monitoring program is one that can be installed in a computer (e.g., server device 10), it may be provided by being stored in a recording medium that can be read by the computer (e.g., a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc.), or it may be provided from outside via a network such as the Internet or a dedicated line.

[0030] (Temperature sensor part) The temperature sensor unit 20 measures the temperature of the overhead power transmission line 2. To this end, the temperature sensor unit 20 is configured to include a sensor main body unit 21 that is attached to each of the multiple overhead power transmission lines 2 supported by the steel tower 1, and an aggregation terminal unit 22 that performs short-range wireless communication with each sensor main body unit 21. The sensor main body unit 21 is configured to obtain a detection signal regarding the temperature of the overhead power transmission line 2, for example, by using a thermocouple directly attached to the overhead power transmission line 2. The aggregation terminal unit 22 is configured to receive the detection signal from each sensor main body unit 21, convert it into temperature measurement data representing the temperature value of the overhead power transmission line 2, and output the temperature measurement data onto the communication line network 23.

[0031] The temperature sensor unit 20 having such a configuration is arranged, for example, at each interval of the steel tower 1, measures the temperature of the overhead power transmission line 2 at each interval of the steel tower 1 at a frequency of every predetermined time (for example, every few seconds to several minutes), and outputs the temperature measurement data, which is the measurement result, onto the communication line network 23. The output temperature measurement data is stored and held in a cloud server on the communication line network 23 as necessary, and then transmitted to the server device 10 in response to a request from the server device 10. However, the arrangement interval, measurement frequency, handling on the communication line network 23, and the like are not limited to a specific embodiment. For example, details of temperature measurement using a sensor can be realized by using a publicly known technology (for example, see JP 2018-201276 A).

[0032] (2) Procedures for monitoring power transmission lines Next, a procedure for monitoring a power transmission line using the power transmission line monitoring system configured as described above, that is, a procedure for a power transmission line monitoring method according to this embodiment will be described.

[0033] Fig. 2 is a flow diagram showing an example of the procedure of the power transmission line monitoring method according to the present embodiment. Fig. 3 is an explanatory diagram showing a specific example of an SAR image processed by the power transmission line monitoring method according to the present embodiment. Figs. 4, 5, 7, and 8 are explanatory diagrams showing a specific example of three-dimensional coordinate space data processed by the power transmission line monitoring method according to the present embodiment. Fig. 6 is an explanatory diagram showing a specific example of resolution conversion processing in the power transmission line monitoring method according to the present embodiment. Fig. 9 is an explanatory diagram showing a specific example of power line sag calculation in the power transmission line monitoring method according to the present embodiment.

[0034] As shown in Fig. 2, when the power transmission line monitoring system is operated, first, pre-processing required for operation is performed (step 101, hereinafter, step is abbreviated as "S"). The pre-processing includes at least a registration process of initial value data (see (a) in the figure), a registration process of a SAR reference image (see (b) in the figure), and a registration process of installation information (see (c) in the figure).

[0035] In the initial value data registration process, the initial value data acquisition unit 12 of the server device 10 receives the laser measurement results of the ground surface shape 5 around the overhead power transmission line 2 to be monitored, which are actually measured using an aircraft such as a helicopter or a drone, and processes the results as three-dimensional data in a predetermined coordinate space, thereby making them initial value data of the ground surface shape 5. Then, the initial value data is registered in a database in a predetermined area of ​​the storage device 11 while being associated with the acquisition date and time of the initial value data.

[0036] In the process of registering the SAR reference image, the displacement data acquisition unit 12 of the server device 10 acquires SAR images of the ground surface shape 5 around the overhead power transmission line 2 to be monitored, which are periodically transmitted from the artificial satellite 31 via the ground station 32, and among the acquired SAR images, the SAR image acquired at the timing closest to the acquisition date and time of the initial value data (including the same timing) is set as the SAR reference image. Then, the SAR reference image is registered in a database in a predetermined area in the storage device 11.

[0037] In the installation information registration process, when information such as the latitude, longitude, height above ground, span length, and position and length of cross arm at which the tower 1 supporting the overhead transmission line 2 is installed is input to the server device 10 as installation information of the overhead transmission line 2, the installation information storage unit 13 of the server device 10 registers the input installation information in a database in a specified area of ​​the storage device 11.

[0038] After the above pre-processing is performed, the power transmission line monitoring system is put into operation. During operation of the power transmission line monitoring system, SAR images are periodically transmitted from the artificial satellite 31 via the ground station 32, and the transmitted SAR images are stored and held in a predetermined area of ​​the storage device 11 in association with the acquisition date and time. In addition, the temperature of the overhead power transmission line 2 to be monitored is measured by the temperature sensor unit 20, and the measurement result, that is, the temperature measurement data, is stored and held in a cloud server on the communication line network 23.

[0039] When the power transmission line monitoring system is in an operational state, it becomes possible to monitor the power transmission line using the power transmission line monitoring system. In the power transmission line monitoring system, the power transmission line monitoring is performed, for example, at a preset periodic timing or at a timing when a change in the ground surface shape 5 is expected due to the occurrence of a disaster or the like.

[0040] When monitoring a power transmission line, in the power transmission line monitoring system, the displacement data acquisition unit 12 of the server device 10 reads and acquires, as the latest SAR image, the SAR image acquired at the timing closest to the date and time of power transmission line monitoring (including the same timing) from the storage device 11 (S102).

[0041] 2, when the latest SAR image is acquired, the displacement amount data acquisition unit 12 reads out and acquires the SAR reference image registered in preprocessing from the storage device 11. Then, image analysis is performed on the latest SAR image and the SAR reference image, and the difference between them is calculated as the amount of displacement over time of the ground surface shape 5. In other words, the displacement amount data acquisition unit 12 calculates the amount of displacement over time of the ground surface shape 5 based on the latest SAR image and the SAR reference image, and the calculation result is used as displacement amount data for the ground surface shape 5 (S103).

[0042] After calculating the displacement amount data, in the server device 10, the distance detection processing unit 15 reads out the installation information stored in the installation information storage unit 13, thereby obtaining information (position, height, etc.) about the tower 1 supporting the overhead power transmission line 2 to be monitored. Furthermore, the distance detection processing unit 15 cuts out an SAR image of the surrounding area including the tower 1, and obtains displacement amount data about the ground surface shape 5 of the surrounding area (S104).

[0043] Specifically, as shown in FIG. 3, for example, the displacement amount data acquisition unit 12 regards area image data in which brightness varies depending on the magnitude of the difference (displacement amount) as displacement amount data, and focuses on the surrounding area including the steel tower 1 supporting the overhead power line 2 to be monitored, and performs image cropping for that surrounding area.

[0044] Then, as shown in FIG. 2, the distance detection processing unit 15 uses the tower 1 supporting the overhead power line 2 to be monitored as a reference and performs coordinate transformation of the ground surface shape 5 of the surrounding area including the tower 1 into a predetermined three-dimensional coordinate space (S105).

[0045] 4, the distance detection processing unit 15 assumes a three-dimensional coordinate space with the position of the ground (foundation) on which the reference tower 1 is installed as the zero point, the height direction of the tower 1 as the z-axis direction, the line direction along which the overhead power transmission line 2 supported by the tower 1 extends as the y-axis direction, and the direction perpendicular to the y-axis and z-axis as the x-axis direction. Then, in the three-dimensional coordinate space, coordinate conversion is performed on the displacement amount data and installation information so that the support position of the overhead power transmission line 2 by the tower 1 and the magnitude of the displacement amount (z value) of the ground surface shape 5 at each point on the xy plane are reflected (see the gray bar plots in the figure).

[0046] Next, as shown in Fig. 2, the distance detection processing unit 15 reads out and acquires the initial value data registered in the pre-processing from the storage device 11. Then, the initial value data is reflected in the three-dimensional coordinate space, thereby synthesizing the initial value data and the displacement amount data. As a result, the distance detection processing unit 15 creates a three-dimensional measurement image reflecting the absolute values ​​in the height direction of the ground surface shape 5 of the area surrounding the steel tower 1 (S106).

[0047] Specifically, as shown in FIG. 5, for example, the distance detection processing unit 15 performs coordinate transformation on the initial value data so that the magnitude (z value) of the initial value data of the ground surface shape 5 at each point on the xy plane is reflected in the three-dimensional coordinate space reflecting the displacement amount data, and thus creates a three-dimensional measurement image.

[0048] As described above, the distance detection processing unit 15 creates a three-dimensional measuring image using the initial value data, the displacement amount data, and the installation information. This three-dimensional measuring image is used to calculate the distance between the overhead power transmission line 2 and the ground surface shape 5 around it.

[0049] In creating such a three-dimensional measuring image, the initial value data and the SAR image on which the displacement amount data is based are not necessarily suitable for processing in the same three-dimensional coordinate space. For example, this is because they generally have different resolutions. Therefore, in the server device 10, the matching processing unit 16 performs a process of matching at least one of the initial value data and the SAR image after the initial value data and the SAR image are acquired and before the three-dimensional measuring image is created. The process performed by the matching processing unit 16 may include various processes including a resolution conversion process.

[0050] Here, the resolution conversion process performed by the alignment processor 16 will be described with a concrete example. As shown in Figure 6, the initial value data and the displacement amount data obtained from the SAR image have different resolutions (data resolution). In addition, because the displacement amount data has undergone coordinate transformation, it is not arranged in a way that matches the y-axis direction (railway direction) and x-axis direction (perpendicular direction) of the three-dimensional coordinate space. Therefore, in order to create a three-dimensional measurement image, it is necessary to group the displacement amount data according to which initial value data it corresponds to. The matching processing unit 16 performs grouping, for example, by the following method. Specifically, when performing grouping, the displacement amount data is divided into meshes, and the initial value data belonging to each region is extracted and labeled (assigned a number label). As a result, the initial value data is assigned the same number label as the displacement amount data that is close in distance on the xy coordinates, and the data is grouped according to the number label. In other words, by grouping using the number label, it becomes clear which initial value data corresponds to which displacement amount data. After grouping, the displacement amount data with the same label number is added to the initial value data to create a three-dimensional measuring image. In other words, even if the resolution (data resolution) of the initial value data and the displacement amount data is different, the difference in resolution between the initial value data and the displacement amount data can be eliminated by adding data with the same numbers while utilizing the grouping result. Although the resolution conversion process using grouping by labeling is taken as an example here, the resolution conversion process performed by the alignment processing unit 16 is not limited to this, and may be performed using other methods. Also, the alignment processing unit 16 may perform processes other than the resolution conversion process as long as they are processes for aligning the initial value data with the SAR image (or the displacement amount data obtained from the SAR image) in order to create a three-dimensional measuring image.

[0051] After performing the alignment process including such a resolution conversion process, the initial value data and the displacement amount data obtained from the SAR image become suitable for processing in the same three-dimensional coordinate space, and as a result, it becomes possible to easily and smoothly create a three-dimensional measuring image.

[0052] After creating the three-dimensional measuring image, the distance detection processing unit 15 uses the three-dimensional measuring image to calculate the distance between the overhead power transmission line 2 and the ground surface shape 5 around it. However, the overhead transmission line 2 is disposed between the steel towers 1. Therefore, sagging (slackness) occurs in the overhead transmission line 2, and the manner in which it occurs (how it sags) is not always constant but can vary depending on the magnitude of the current and meteorological conditions (weather, temperature, wind conditions, etc.). The sag of the overhead transmission line 2 has a large effect on the calculation result of the distance from the ground surface shape 5, so it is desirable to grasp it in advance when calculating the distance. However, for that purpose, it is not necessarily realistic to comprehensively detect the weather conditions at the installation location of the overhead transmission line 2 or to identify the correspondence between the change in the weather conditions and the fluctuation in the occurrence mode of the sag. In addition, although it is conceivable to adopt the sag (fixed value) calculated under predetermined conditions, this does not reflect the fluctuation in the occurrence mode of the sag, and it cannot be said that the sag of the overhead transmission line 2 can be grasped with high accuracy.

[0053] It is considered that the expansion and contraction of the overhead transmission line 2 in the line direction has a large effect on the sag of the overhead transmission line 2. One of the factors that expands and contracts the overhead transmission line 2 is the temperature change of the overhead transmission line 2. The temperature of the overhead transmission line 2 can change due to various factors, including changes in the magnitude of the current and weather conditions. In other words, it can be considered that the major factor that changes the occurrence mode of the sag of the overhead transmission line 2 is the temperature change of the overhead transmission line 2.

[0054] In this embodiment, as shown in Fig. 2, when calculating the distance between the overhead transmission line 2 and the ground surface shape 5, the electric wire sag calculation unit 14 accesses a cloud server on the communication line network 23. Then, the electric wire sag calculation unit 14 acquires temperature measurement data detected by the temperature sensor unit 20 for the overhead transmission line 2 to be monitored from the cloud server (S107). At this time, the electric wire sag calculation unit 14 may acquire only the temperature measurement data (i.e., the latest temperature measurement data) that is the detection result at the timing closest to the calculation date and time of the distance (including the same timing), or may acquire all the temperature measurement data detected during a predetermined period (for example, from the previous calculation of the distance to the current calculation of the distance).

[0055] Then, when the temperature measurement data is acquired, the electric wire sag calculation unit 14 extracts one of the temperature measurement data used for calculating the sag of the overhead transmission line 2 from the acquired temperature measurement data (S108). For example, if only the latest temperature measurement data is acquired, the temperature measurement data is extracted. If all the temperature measurement data obtained in a predetermined period are acquired, for example, the latest temperature measurement data may be extracted from the data. By extracting the latest temperature measurement data in this way, the temperature of the overhead transmission line 2 at the time of calculating the sag can be reflected in the calculation result of the sag. Also, if all the temperature measurement data obtained in a predetermined period are acquired, for example, the highest temperature measurement data may be extracted from the data. By extracting the highest temperature measurement data within the predetermined period in this way, the sag of the overhead transmission line 2 can be calculated assuming the worst condition in which the overhead transmission line 2 is most likely to sag.

[0056] When any one of the temperature measurement data is extracted, the electric wire sag calculation unit 14 uses the extracted temperature measurement data to calculate the sag of the overhead transmission conductor 2 (S109). The sag calculation is performed, for example, in the following procedure.

[0057] When calculating the conductor sag from temperature measurement data, the conductor tension is calculated first. For example, the actual conductor length in the standard state (maximum usable tension T0 at wind speed 40 m / s and conductor temperature t0 (=15°C)) is taken as L0. If the conductor tension when the conductor temperature reaches t1 is T1 and the actual conductor length is L1, the conductor temperature t1 and conductor tension T1 can be expressed by the following relational formula. The conductor tension T1 is calculated from this relational formula.

[0058]

number

[0059] After calculating the conductor tension T1, the conductor sag is calculated. For example, as shown in Figure 9, the conductor sag d is calculated by the three-point angle method from the conductor at an arbitrary point D in the figure, the elevation angles of points A, B, and D shown in the figure, the horizontal angle between A'B' and A'D', and the relationship between the span length S and the difference in height of the support h. The relational equation between the conductor tension T1 and the conductor sag d is as follows:

[0060]

number

[0061] After the calculation of the conductor sag, the conductor sag calculation unit 14 uses the calculated conductor sag value to calculate a conductor catenary curve that represents the occurrence of sag in the overhead transmission line 2, as shown in Fig. 2. The conductor sag calculation unit 14 then reflects the conductor catenary curve in the three-dimensional measuring image created for the distance calculation (S110). There are no particular limitations on the method for calculating the conductor catenary curve and drawing it in the three-dimensional measuring image, and any known method may be used.

[0062] As a result, the occurrence of sagging in the overhead transmission line 2 supported by the tower 1 is depicted in the three-dimensional measuring image, as shown in FIG.

[0063] When multiple overhead transmission lines 2 are supported on the tower 1, the electric wire sag calculation unit 14 performs the above process for each of the overhead transmission lines 2. However, this is not necessarily limited to this, and the electric wire sag calculation unit 14 may select at least one of the multiple overhead transmission lines 2 (for example, an overhead transmission line 2 located close to the ground surface) and perform the process only for the selected overhead transmission line 2.

[0064] Thereafter, the distance detection processing unit 15 calculates and obtains the distance between the overhead power transmission line 2 and the surrounding ground surface shape 5 in the three-dimensional measurement image reflecting the power transmission line catenary curve, as shown in Fig. 2. Then, the distance detection processing unit 15 judges whether or not there is an abnormality in the calculated distance (S111).

[0065] The calculation of the separation can be performed by, for example, finding the shortest distance between the top of the ground surface shape 5 in the height direction and the overhead power transmission line 2 for each point on the xy plane in the three-dimensional measurement image, and extracting the shortest distance that is closest (smallest) among the points (see the arrows in the figure). In other words, the value of the shortest shortest distance is the calculation result of the separation between the overhead power transmission line 2 and the ground surface shape 5, as shown in Figure 8.

[0066] The presence or absence of an abnormality in the calculation result of the separation may be determined by comparing the calculation result with a preset allowable value. Specifically, for example, if the calculation result of the separation is equal to or greater than the allowable value, the separation detection processing unit 15 determines that there is no abnormality in the separation between the overhead transmission line 2 and the ground surface shape 5. On the other hand, if the calculation result of the separation is less than the allowable value, the separation detection processing unit 15 determines that the separation between the overhead transmission line 2 and the ground surface shape 5 has not been secured and that an abnormality has occurred in the separation.

[0067] When the distance detection processing unit 15 determines that an abnormality has occurred in the distance, the server device 10 outputs an alarm to that effect through a display output unit of the server device 10 or a terminal device or the like communicably connected to the server device 10. This allows the user of the server device 10 or the terminal device or the like to know that an abnormality has occurred in the distance between the overhead power transmission line 2 and the ground surface shape 5.

[0068] (3) Effects of this embodiment According to this embodiment, one or more of the following advantages are achieved.

[0069] (a) According to this embodiment, the separation between the overhead power transmission line 2 and the ground surface shape 5 is calculated using initial value data obtained by actually measuring the ground surface shape 5 using an aircraft, displacement amount data on the ground surface shape 5 obtained by analyzing SAR images periodically sent from the artificial satellite 31, and installation information of the overhead power transmission line 2, and the result is set as the measurement result of the separation. In this way, by using the displacement amount data, it is possible to reflect the displacement occurring in the ground surface shape 5 in the isolated measurement without performing an actual measurement using an aircraft for each isolated measurement. Furthermore, since not only the displacement amount data but also the initial value data obtained by actual measurement are used, the ground surface shape 5 can be measured with high accuracy, and the result of the isolated measurement becomes highly reliable. In other words, according to this embodiment, even if the distance between the overhead transmission line 2 and the ground surface shape 5 is measured periodically to monitor whether there is any abnormality in the distance, the measurement can be performed accurately while reflecting any displacement occurring in the ground surface shape 5, and the time and cost required for the measurement can be reduced without being dependent on the weather, etc.

[0070] (b) According to this embodiment, the amount of displacement of the ground surface shape 5 is calculated based on the SAR reference image acquired at the timing closest to the acquisition of the initial value data and the latest SAR image acquired at the timing closest to the date and time of power line monitoring (i.e., the date and time of the separation calculation), and the calculated amount of displacement is used as displacement amount data. Therefore, the measurement result of the separation between the overhead power transmission line 2 and the ground surface shape 5 reliably reflects the amount of displacement of the ground surface shape 5 from the acquisition of the initial value data to the date and time of the power line monitoring. This makes the result of the separation measurement very reliable.

[0071] (c) According to this embodiment, the sag of the overhead transmission conductor 2 is calculated using the temperature measurement data obtained by the temperature sensor unit 20, and the calculated sag of the overhead transmission conductor 2 is taken into consideration to calculate the distance between the overhead transmission conductor 2 and the ground surface shape 5. Therefore, even if the manner in which the sag of the overhead transmission conductor 2 occurs (how much it hangs down) varies depending on the magnitude of the current, weather conditions, and the like, it is possible to accurately grasp the sag of the overhead transmission conductor 2 while reflecting the variation. In other words, according to this embodiment, the distance between the overhead transmission conductor 2 and the ground surface shape 5 can be accurately measured while reflecting the variation in the manner in which the sag of the overhead transmission conductor 2 occurs, and as a result, the result of the isolation measurement becomes highly reliable.

[0072] (d) As described in this embodiment, when calculating the sag of the overhead transmission conductor 2, if the latest temperature measurement data obtained closest to the time of the remote measurement is used, the temperature of the overhead transmission conductor 2 at the time of calculating the sag can be reflected in the calculation result of the sag. In other words, the temperature measurement data is reflected in real time, which is suitable for knowing the current result of the remote measurement.

[0073] (e) As described in this embodiment, when calculating the sag of the overhead transmission conductor 2, if the highest temperature measurement data among the temperature measurement data obtained in a predetermined period is used, the sag of the overhead transmission conductor 2 can be calculated assuming the worst condition in which the overhead transmission conductor 2 is most likely to be sag. In other words, the temperature measurement data in the so-called worst case is reflected, which is suitable for knowing the results of isolated measurement taking into account the degree of risk.

[0074] (f) As described in this embodiment, by performing a process to align the initial value data with the SAR image on which the displacement amount data is based, the initial value data and the SAR image become suitable for processing in the same three-dimensional coordinate space, and as a result, it becomes possible to easily and smoothly create a three-dimensional measuring image.

[0075] <Modifications, etc.> Although one embodiment of the present disclosure has been specifically described above, the present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present disclosure.

[0076] For example, in the above embodiment, the observation data periodically transmitted from the satellite is SAR images, but the present invention is not limited to this. The observation data may be replaced with something other than SAR images as long as it can identify the amount of displacement of the earth's surface shape 5 over time without requiring actual measurements using an aircraft.

[0077] In the above-described embodiment, the case where the sag of the overhead transmission line 2 is calculated using temperature measurement data in measuring the distance between the overhead transmission line 2 and the ground surface shape 5 is described as an example, but the present invention is not limited to this. For example, the distance between the overhead transmission line 2 and the ground surface shape 5 may be calculated using a sag (fixed value) calculated under predetermined conditions, and even in this case, the distance can be measured with high accuracy while reflecting the displacement occurring in the ground surface shape 5. However, as described in the above-described embodiment, if the sag of the overhead transmission line 2 is calculated using temperature measurement data, the result of the distance measurement becomes very reliable as described above, which is very useful in that respect.

[0078] In the above embodiment, the case where the sag of the overhead transmission conductor 2 is calculated by first calculating the conductor tension and then calculating the conductor sag is described as an example, but the present invention is not limited to this. In other words, the calculation of the sag of the overhead transmission conductor 2 is not limited to a specific calculation method.

[0079] <Preferred aspects of the present disclosure> Preferred aspects of the present disclosure will be described below.

[0080] (Appendix 1) According to one aspect of the present disclosure, an initial value data acquisition unit that acquires three-dimensional data of a ground surface shape in an area where the overhead power transmission line is arranged, the data being measured using an aircraft, as initial value data; a displacement amount data acquisition unit that acquires and analyzes observation data regarding the earth's surface shape periodically transmitted from a satellite, extracts a displacement amount of the earth's surface shape over time, and sets the displacement amount data; An installation information storage unit that stores installation information of the overhead power transmission line; a distance detection processing unit that calculates a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power transmission line monitoring system is provided, comprising:

[0081] (Appendix 2) Preferably, The displacement amount data acquisition unit sets the displacement amount between the ground surface shape specified by the observation data acquired at the timing closest to the data acquisition by the initial value data acquisition unit and the ground surface shape specified by the observation data acquired at the timing closest to the distance calculation by the distance detection processing unit as the displacement amount data. There is provided a power line monitoring system as set forth in claim 1.

[0082] (Appendix 3) Preferably, A temperature sensor unit for measuring a temperature of the overhead transmission line; a wire sag calculation unit that calculates a sag of the overhead transmission line using temperature measurement data obtained by the temperature sensor unit, The distance detection processing unit calculates a distance between the overhead transmission line and the ground surface shape by taking into account the sag of the overhead transmission line calculated by the electric wire sag calculation unit. There is provided a power line monitoring system according to claim 1 or 2.

[0083] (Appendix 4) Preferably, The electric wire sag calculation unit calculates the sag of the overhead transmission line by using the temperature measurement data obtained at a timing closest to the time when the separation detection processing unit calculates the separation. There is provided a power line monitoring system as set forth in Appendix 3.

[0084] (Appendix 5) Preferably, The electric wire sag calculation unit calculates the sag of the overhead transmission conductor using the highest temperature measurement data among the temperature measurement data obtained during a predetermined period until the separation detection processing unit calculates the separation. There is provided a power line monitoring system as set forth in Appendix 3.

[0085] (Appendix 6) Preferably, A matching processing unit that performs a process of matching the initial value data and the observation data on which the displacement amount data is based. According to an aspect of any one of claims 1 to 5, there is provided a power transmission line monitoring system.

[0086] (Appendix 7) According to another aspect of the present disclosure, An initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage procedure for storing installation information of the overhead power transmission line; a distance detection process step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A method for monitoring a power transmission line is provided, comprising:

[0087] (Appendix 8) According to yet another aspect of the present disclosure, On the computer, an initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which data is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage step of storing installation information of the overhead power transmission line; a distance detection processing step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power line monitoring program is provided that causes the power line monitoring program to execute the following: [Explanation of symbols]

[0088] 1. Steel Tower 2. Overhead lines 3. Trees 4 Constructions 5 Ground surface shape 10. Server device 11 Storage device 12 Initial value data acquisition section 13 Displacement data acquisition section 14 Installation information holding section 15 Wire slack calculation section 16 Distance detection processing unit 17 Matching processing section 20 Temperature sensor section 21 Sensor body 22 Aggregation terminal unit 31 Satellite 32 Ground Station

Claims

1. an initial value data acquisition unit that acquires three-dimensional data of a ground surface shape in an area where the overhead power transmission line is arranged, the data being measured using an aircraft, as initial value data; a displacement amount data acquisition unit that acquires and analyzes observation data regarding the earth's surface shape periodically transmitted from a satellite, extracts a displacement amount of the earth's surface shape over time, and sets the displacement amount data; An installation information storage unit that stores installation information of the overhead power transmission line; a distance detection processing unit that calculates a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power transmission line monitoring system comprising:

2. The displacement amount data acquisition unit sets the displacement amount between the ground surface shape specified by the observation data acquired at the timing closest to the data acquisition by the initial value data acquisition unit and the ground surface shape specified by the observation data acquired at the timing closest to the distance calculation by the distance detection processing unit as the displacement amount data. The power transmission line monitoring system according to claim 1 .

3. A temperature sensor unit for measuring a temperature of the overhead transmission line; a wire sag calculation unit that calculates a sag of the overhead transmission line using temperature measurement data obtained by the temperature sensor unit, The distance detection processing unit calculates a distance between the overhead transmission line and the ground surface shape by taking into account the sag of the overhead transmission line calculated by the electric wire sag calculation unit.

3. The power transmission line monitoring system according to claim 1 or 2.

4. The electric wire sag calculation unit calculates the sag of the overhead transmission line by using the temperature measurement data obtained at a timing closest to the time when the separation detection processing unit calculates the separation. The power transmission line monitoring system according to claim 3 .

5. The electric wire sag calculation unit calculates the sag of the overhead transmission conductor using the highest temperature measurement data among the temperature measurement data obtained during a predetermined period until the separation detection processing unit calculates the separation. The power transmission line monitoring system according to claim 3 .

6. A matching processing unit that performs a process of matching the initial value data and the observation data on which the displacement amount data is based. A power transmission line monitoring system according to any one of claims 1 to 5.

7. An initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage procedure for storing installation information of the overhead power transmission line; a distance detection process step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power transmission line monitoring method comprising:

8. On the computer, an initial value data acquisition step of acquiring three-dimensional data of the ground surface shape of the area where the overhead power transmission line is arranged, which data is actually measured using an aircraft, as initial value data; a displacement amount data acquisition step of acquiring and analyzing observation data regarding the earth's surface shape periodically transmitted from a satellite, and extracting a displacement amount over time of the earth's surface shape to obtain displacement amount data; An installation information storage step of storing installation information of the overhead power transmission line; a distance detection processing step of calculating a distance between the overhead power transmission line and the ground surface shape using the initial value data, the displacement amount data, and the installation information; A power line monitoring program that executes the above.

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